Engine compressor



Dec. 3, 1929. H. N. SCHRAMM ENGINE COMPRESSOR Filed April 23, 1927 2Sheets-Sheet l Dec. 3, 1929. H. N. SCHRAMM ENGINE COMPRESSOR Filed April23, 1927 2 Sheets-Sheet Patented Dec 3, 1929 UNITED STATES PATENT OFFICEENGINE COMPRESSOR Application filed April 23,

This invention relates to engine driven pumps and more particularly toair compressors operated by internal combustion engines.

The principal object of my invention is the production of an engine-pumpunit comprising a one piece block having a number of cylinders andbearings for a crank shaft, and having pistons in the cylinders, byproviding a head for the cylinders comprising combustion chambers andfuel intake and exhaust ports for an even number of the cylinders, andwith air inlet and outlet ports for the remaining cylinder or cylinders.

A still further object of my invention is the conversion of amulticylinder engine into an engine-pump by converting one or morecylinders into air pump cylinders and leaving an evennumber of thecylinders unconverted.

A still further object of my invention is the conversion of a standardfour cycle automobile engine into an engine pump. adapted to compressair'at each power stroke of the engine. a

With the above and related objects this in ventioncomprises an improvedengine-pump unit and the art for the production thereof which ishereinafter more fully described and claimed, and a preferred embodimentwhereof is illustrated in the accompanying drawing, it being understoodthat various changes in the construction, combination, arrangement andother details may be made without departing from the spirit of myinvention and to be within the scope of my claims.

In the said drawing Fig. 1 is an elevation of the engine-pump shown inconneclion with an air tank.

Fig. 2 is a plan view thereof with the head of the engine-pump unitremoved.

Fig. 3 is a section on the lines 3-3 of Fig. 2.

192?. Serial No. 186,098.

Fig. 4 is a section on the lines 4% of Fig. 2.

Referring to the drawing for a detail description of my invention, acrank shaft 5 of a type used in standard four cycle automobile enginesis supported by bearings 6 in the lower portion of easing 7, the upperportion of the casing being comprised of four cylinders, two endcylinders 8 and two intermediate cylinders 9. Each cylinder is providedwith a standard type piston and is connected by a rod 10 with the crankshaft. The casing is provided with a head 12, which, except for thehereinafter described moditications, is of the type used in connectionwith a standard automobile engine.

The portions of the head 12 which are shown as constituting the tops ofthe end cylinders are provided with air or other fluid intakes 13 andwith outlets 14:, while the central portion of the head is provided withcombustion chambers 15 and fuel intakes controlled by valves 16. Eachend portion 17 of the head centrally of its end cylinder 8 is providedwith a port 18 vadapted to be closed by a disc valve 19 thereundermounted upon a stem 20 provided with a foot 21 connected with the valve19 by cushioning springs as shown. The stem 20 is provided with a pistonhead 23 for a cylinder 24, the piston being adapted to be actuated by aspring thereunder wound about the stem 20.

During the downward stroke of a pump cylinder piston, the air throughthe inlet 13 causes the valve 19 to slide downwardly of the stem 20 andto place the springs connecting the valve with the foot 21 undertension, so that at the commencement of the return stroke this tensionis released and permits the valve to quickly close the port. The foot 21tends to follow the springs connecting it with the valve, causing thestem 20 to tend to force the piston 23 inwardly of the cylinder 24,which tendency is resisted by the stout spring thereunder.

' 26 of the ports 18 and a The portions 17 of the head 12 above the endcylinders 8 are provided with an outlet chambers in the rear of theinlet chambers partition 27 separating each chamber 25 from thecorresponding chamber 26. Each of the chambers 25 is provided with aport 28, controlled by a disc valve 29 on top of the port, said valvebeing connected by a spring with the foot 30 of a bolt32projectedthrough a cover 33 closing'the chambers 25 and 26 of each ofthe end cylinders 8.v The portion of the bolt 32 above the head 33 isthreaded for a lock nut 34 whereby the tension of the spring connectingthe bolt 32 with the valve 29 may be varied. The stem 20 carrying thevalve 19 is similarly threaded for a nut 35 to adjust the tension of thespring above it whereby the tendency of the stem 20 to force the piston23 inwardly of the cylinder 24 is resisted.

The air outlets 14 are connected with an air pipe 36 leading into an airtank 37. The casing as well as the head of the engine-pump is providedwith a water jacket 38, and the portion of the head of the intermediatecylinders 9 is provided with spark plug holes 39.

With the hereinbefore described difference between the end portions 17of the enginepump and that of a standard four cylinder automobileengine, a two cylinder enginepump is produced which operates in thefollowing manner :With the positions of the pistons shown in Fig. 1, theintake ports 18 of the end cylinders 8 Will be understood by thoseskilled in the art to be closed by their respective valves 19, while oneof the pistons of the cylinders 9 is at the beginning of its compressionstroke and the other at the beginning of its scavenging stroke. Duringthe next quarter of a cycle, the intake ports of the end cylinders willopen and their outlet ports will close and air will flow into saidcylinders through the intakes 13. During the next quarter one of thepistons of the cylinders 9 will complete its power stroke and the otherits suction stroke, While the pistons of the end cylinders will completetheir compression strokes causing the closing of their intake ports andthe opening of their outlet ports to allow the air to flow through bothoutlets 14 into the pipe 36 and into the tank 37. During the thirdquarter of the cycle, the piston which completed the power stroke willcause the scavenging of its cylinder while the piston which completedthe suction stroke will complete its compression stroke, during whichquarter the pistons of both end cylinders will cause the opening oftheir respective inlet ports to take in air through the inlets 13.During the fourth quarter of the cycle, the piston which completed itscompression stroke will complete its power stroke and the one whichcompleted its scavenging stroke will complete its suction stroke, whilethe pistons of both end cylinders will jointly cause the closing oftheir respective inlet ports and the opening of the outlet ports and theair will flow through both outlets 14 into the pipe 36 and tank 37. Itwill thus be seen that the engine operates as a two cycle engine, thatis having two power strokes per cycle, while the pump operates as asingle cylinder pump, since both cylinders take in and compress airsimultaneously twice during each cycle. The reason for having two pumpcylinders instead of one is for the sake of uniformity and probably alsothat two smaller air inlets are more efficient than one large air inlet.

It will be further understood that the engine pump will operate just asefficiently and in the hereinbefore described manner if the twointermediate cylinders should be made air cylinders and the two end onesengine cylinders.

A six cylinder engine-pump could be produced in the same manner to looklike a duplicate of a six cylinder standard automobile engine to operateas a four cycle engine-compressor by modifying a portion of the cylinderhead of the end of the two intermediate cylinders.

It will be understood that an eight cylinder engine can, in the samemanner, be converted into a one or two cylinder compressor and a sixcylinder engine, the compressor to operate as a one cylinder pump andthe engine cylinders to operate as a three cycle engine.

I have shown, thus far, how to make a one piece engine compressor bychanging the cylinder head of a standard automobile engine, but I do notwish to limit myself to the use of the standard crank shaft, provided myengine compressor consists of a one-plece casing, head and crank shaft.

My invention is, therefore, not limited in any way to the precisearrangements described and shown, but that it may be modified in any waywhich the requirements or the conditions of practical Work may rendernecessary or advantageous without departing from its nature.

What I claim is:

1. In an engine-pump unit, the combination of a block having cylinderstherein, a crank shaft, pistons connected to the crank shaft andreciprocable in the cylinders, and a cylinder head constructed toreplace the normal cylinder head for the block and provided with certainportions arranged to cover certain of the cylinders to render themengine cylinders and with other portions carrying valves and arranged tocover others of the cylinders to render them pump cylinders.

2. In an engine-pump unit, the combination of a block having cylindersand corresponding vapor passages therein, a crank shaft, pistonsconnected to the crank shaft and reciprocable in the cylinders, and acylinder head constructed to replace the normal cylinder head for theblock and provided with certain portions arranged to cover certain ofthe cylinders to render them engine cylinders and with other portionscarrying valves and arranged to cover others of the cylinders to renderthem pump cylinders, said head being also arranged to cut oflcommunication between the pump cylinders and their corresponding vaporpassages.

In testimony whereof I have attached my signature to this specification.

HENRY N. SCHRAMM.

